The present invention relates generally to a vehicular headlamp for use on, for example, an automobile, and more particularly to a vehicular headlamp in which a reflector is tiltably supported in a lamp body by means of an aiming mechanism, and an orthogonal conversion gear mechanism having an rotational operating shaft for rotation of an aiming screw is disposed on the rear wall of the lamp body.
A conventional headlamp of this type, as shown in FIG. 7, is provided with a lamp body 1 and a reflector 2 accommodated in the lamp body 1, which reflector is supported by an aiming screw 3 constituting a part of an aiming mechanism, as disclosed in Unexamined Japanese Patent Application No. Hei. 5-258602. The aiming screw 3 is rotatably supported on the rear wall of the lamp body 1. A rotational operating shaft 4 extends upward along the rear wall of the lamp body 1. An orthogonal conversion gear mechanism 5 constituted by gears 5a, 5b, 5c and 5d is provided between the rotational operating shaft 4 and a rear end part of the aiming screw 3 projecting rearward from the rear wall of the lamp body 1, so that the aiming screw 3, linked with the rotational operating shaft 4, is rotated when the shaft 4 rotates. A nut 2a fitted on the rear side of the reflector 2 threadably engages a front end part of the aiming screw 3. With this structure, when the aiming screw 3 is rotated, the nut 2a moves back and forth on the aiming screw 3 so that the reflector 2 is tilted.
In the conventional headlamp as described above, since the orthogonal conversion gear mechanism 5 protrudes rearward a significant distance, the mechanism 5 can rather easily be struck against the vehicle body when the headlamp is assembled to the vehicle so that the orthogonal conversion gear mechanism may be damaged.